It is understood that Mr Robinson's condition has since stabilised after he had a stent fitted.

On Tuesday night he was visited by senior figures within the DUP and briefed on the latest row concerning the proposed reforms to the welfare system.

It is no secret that the relationship between the First Minister and his deputy is not as warm as the one that developed between his predecessor Ian Paisley and Mr McGuinness.

However, it can be revealed that Mr McGuinness has been in frequent contact with Mr Robinson during his illness, by phone and also in person. Last night Sinn Fein confirmed that not only has Mr McGuinness been in contact with Mr Robinson by phone, but he has also been in person to visit him at the Royal Victoria Hospital in Belfast.

Both share a love of football, and banter about the rivalry between the two top Premiership teams they support.

Speaking in Stormont on Monday, Mr McGuinness himself dispelled the tension rumours.

"In terms of my relationship with Peter, nothing could be further from the truth... I think that he has made a major contribution to the progress that we have made over the past eight years," he told the Assembly.

"It is cause of great concern that someone like him should be hospitalised."

The DUP has not appointed a temporary replacement to stand in for Mr Robinson as he recovers.

DUP deputy leader Nigel Dodds said the party has not taken any decision yet in that regard.

Colleagues have reported that Mr Robinson is in good form in hospital and appears to be recovering well, although he may remain in hospital for a few more days.